Lecture 20: Dairy Calf Nutrition

newborn calf challenges

• naive immune system → partially developed, but suppressed at birth; environment contained

• poor thermoregulation → lack of fat, lack of muscle tone

• risk of hypoglycemia

preventing disease in newborn calves

• provide adequate colostrum

• maintain clean environment

• minimize heat loss

immediate care of newborn calf

• dry calf

• dip navel (7% iodine)

• separate from dam

• hand-feed colostrum

what is colostrum?

• first milk produced after parturition → up to 6 milkings but only 1st milking is high quality

• high in dry matter content

• high in IgG → largest antibody component in milk

after the 1st milking, the rest of the milkings are

transitional

other antimicrobial factors in milk

• IgA → secretory IgA locally produced in mammary gland as well as derived from blood

• lactoferrin, other peptides and enzymes produced by mammary epithelial cells

why does colostrum matter?

• provides passive immunity

• essential for disease prevention

gut closure

• intestinal absorption of antibodies declines rapidly → begins to decline immediately and decreases linearly

• gut closure by 24 hours

• feed early for maximum absorption

timeline for absorption of antibodies

• by 6 hours → ability to absorb has decreased by 30%

• by 8 hours → decreased by 50%

colostrum feeding protocol

• ideal: feed full amount (3-4 quarts) within 2-4 hours via voluntary consumption or feeding tube

• if half to two thirds are consumed within 2 hours, feed remainder by no later than 12 hours

colostrum volume guidelines

• amount to feed according to BW

• 50-100 lbs, feed 3 quarts

• <50 lbs, feed 2 quarts

• >100 lbs, feed 4 quarts

• reluctant calves should be tube-fed

measuring colostrum quality

• colostrometer to assess colostrum quality

• adequate IgG in colostrum to be considered high quality: >50-60 g/L

colostrometer

• a hydrometer → measures specific gravity

• converts specific gravity to IgG concentration

IgG in milk varies from

20 to >100 mg/ml

assessing pain transfer

• measure total plasma protein using refractometer

• goal: >5.5 g/dL total plasma protein (indicates adequate colostrum meal)

failure of passive transfer

• 40% of calves affected

• increased disease risk

• increased mortality

critical level serum IgG

>8 g/L (0.8 g/dL)

risk factors for poor immunity

• heifer colostrum

• colostrum leakage pre-calving

• delayed feeding

• low IgG concentration

attaining adequate immunity depends on

adequate production of colostrum

adequate production of colostrum depends on

adequate nutrition

what produces less volume with lower IgG concentrations than cows?

heifers

high volume does not always equal

high quality colostrum

attaining adequate immunity depends on

adequate antibody content

adequate antibody content

• concentration declines if colostrum leaks before parturition

• concentration declines rapidly with milking

• heifers → lower Ig levels than cows

• high-producing cows → tend to produce colostrum with lower Ig levels

frozen colostrum

• use from a cow in the same herd

• must be from BLV-negative and Johne’s negative cows

colostrum replacer

>80 g Ig (adequate)

colostrum supplement

• can be added to low quality colostrum

• do not use alone

when does gut permeability begin to decline?

immediately

feeding timeline

• colostrum (birth)

• milk/milk replacer (0-6 weeks)

• starter introduction (7 days)

• weaning transition

milk feeding basics

• feed >10% BW (ideal: 15-20%)

• divide into 2 feedings daily

• calf on a cow will nurse 7-10 times daily and may ingest 10 L of milk

whole milk or waste milk

• can use surplus transition milk or regular surplus milk

• can add milk replacer if needed

use caution with mastitis milk because

• pasteurize it

• do not feed to newborn calves due to increased gut permeability and risk of bacteria transfer

milk replacer

• prefer dairy-based replacers

• mix by weight → use warm water

• feed twice daily

minimum milk feeding should be

10% BW

conventional feeding system

• limit expensive milk replacer

• intake: lower milk

• goal: encourage starter intake → relies more on starter for growth

accelerated feeding system

• intake: higher milk

• goal: faster growth → shorter intake lags at first, catches up later

esophageal groove

• milk bypasses rumen

• fold of reticulum forms a groove between esophagus and reticulo-omasal orifice

• connects cardia region to omasum

milk digested in abomasum

• clot in abomasum → casein and fat

• rennin binds casein, clot digested slowly over 12-18 hours

• whey is composed water, minerals, lactose, other proteins → goes straight to SI

rumen development

• stimulated by starter intake

• grain → volatile fatty acid production → stimulation of rumen development

hay feeding

• grain more important than hay for rumen development

• introduce hay after weaning → alfalfa best

• reduces non-nutritive sucking

hygiene

• clean feeding equipment

• whole milk or milk replacer should contain <10,000 CFU/ml bacteria and no coliform contamination

• use gloves or thoroughly wash hands to reduce pathogen transfer

water

• provide free-choice water

• especially important in sick calves

starter feeding

• introduce at 7 days

• pellets, meal, highly palatable, high-quality protein

• provide small, fresh amounts daily

scours

• infection → rotavirus, coronavirus, cryptosporidium, coccidia, E. coli, salmonella, clostridium

• dietary management → ingesting dirt or sand

concerns with scours

loss of water and electrolytes, inflammation in intestines, loss of ability to absorb nutrients → hypoglycemia

starvation

• poor intake due to poor management or intentional restriction

• poor milk replacer quality

• indicated by lack of fat at necropsy

weaning criteria

• eating 2-2.5 lb starter/day

• consistent intake for 3 days

weaning process

• gradually reduce milk amount and feed once per day

• transition to group housing

• feed ad libitum starter and hay